Tire building drum



Aug. '8, 1939.

H. C. BOSTWICK TIRE BUILDING' DRUM Filed March 23, 195'? 3 Sheets-Sheet l llllllll.'

Aug. 8, 1939. H. c, BosTw|cK TIRE BUILDING DRUM Filed March 23, 1957 3 Sheets-Sheet 2 L. C @ama/i,

Aug. 8, 1939 H. c, BosTwlcK l TIRE BUILDING DRUM I5 Sheets-Sheet 3 A Filed March 23, 1937 7 ////////w&\\\\\\\\\\ ,Illll Patented Aug. 8, 1939 UNITED STATES PATENT OFFICE TIRE BUILDING DRUM Ohio Application March .23, 1937, Serial No. 132,500

12 Claims.

This invention relates to collapsible forms or drums for building pneumatic tire casings such as sem-ilat bands which require further shaping by expanding the tread and drawing the beads 5 together to bring the band to tire form.

One of the main purposes of the invention is to provide a novel combination of inner drum or core portion, whose body is preferably made collapsible after the manner disclosed in my prior 1`0 Patents 2,042,498 of June 2, 1936, or 2,020,497 of November 12, 1935, or in the improved manner herein disclosed, or any equivalent thereof, with an independently collapsible outer drum or body portion, and preferably also with independently l collapsible, undercut bead-seating rings, to the end that such drums may be made deepercrowned than heretofore, and still be easily withdrawable from the tire-band built thereon.

A further object is to provide an improved drum body, collapsible to a greater extent than heretofore, for use either as the inner core of such a combination or as the outer body of a drum on which a tire-forming band may be built.

Of the accompanying drawings, Fig. 1 is a rear end elevation, in section through the central shaft and control sleeve, showing a preferred form of my improved drum, in an expanded condition.

Fig. 2 is a side elevation, partly broken away and in section, on the plane 2-2 of Fig. l.

Fig. 3 is a detail end elevation illustrating one mode of operating the key segment of one of the end rings, which is shown partly withdrawn.

Fig. 4 is an end elevation corresponding to Fig. l, partly in section without the bead-seating end rings.

Fig. 5 is an end elevation showing the collapsed condition of the outer drum body.

o Fig. 6 is a detail interior face view of the outer drum body, from the plane 6 6 of Fig. 4, showing the connectors for its abutting end Segments.

Fig. '7 is a rear end elevation corresponding to Fig. 1, of my improved drum structure, usable either as the body of a drum on which to build a tire, or as the inner body of the combination disclosed in the preceding views.

Fig. 8 is an axial section on the line 8 8 of Fig. 7.

Fig. 9 is an end elevation of said drum structure in a fully collapsed condition.

Figs. 10 and l1 are detail sections showing the segments of the drum structure provided respectively with detachable and with integral or xed 56 bead-seating end flanges.

Referring at rst to Figs. 1 to 6 inclusive of the drawings, 20 is the horizontal shaft of a tirebuilding machine, normally rotating in the direction of arrow A in Fig. l and carrying the tire-building drum at its outer end. Said drum 5 comprises a collapsible inner drum body 2| which, though here illustrated as embodying improvements making it collapsible to a greater extent than heretofore, could employ the body structure of many of the Well-known chucks or drums 10 previously used as tire-band building forms, an .independently collapsible outer drum or body 22 of improved construction, and a pair of independently collapsible bead-seating end rings 23.

The inner drum body 2| is composed of central 15 supporting and operating means carrying a series of arcuate segments in two opposite sets or groups and collectively forming, when expanded, a cylindrical surface, as hereinafter described, for supporting the segmental outer drum body, and 20 both of said drum bodies are provided with widthwise adjustments, as will be pointed out. The edges of both drum bodies are further formed to intert with the detachable, segmental bead rings, as will appear. 25

The outer drum body 22, whose substantially cylindrical periphery forms the middle portion of the band-building surface, is composed of a suitable number, such as five, of segments 24, 25, 26, 2l and 28, connected in series by hinges 29 30 and adapted to fold from both ends into abutting groups of three and two segments respectively, as represented in Fig. 5, for removal from the tire band. The two end segments 24 and 28 have their terminal edges 3D, 3| beveled respectively 35 in underlapping and overlapping relation and adapted to be held together in substantially abutting relation by a pair of connector plates 32 each detachably held by bolts 33 upon a pair of conical lugs 34 formed on the respective segment 40 ends and intertting with complementa] conical seats on the plate.

The peripheral portion or shell of the outer drum body 22 is spaced from the inner drum body 2| by a series of radial lugs 35, in at least two 45 circumferentially spaced locations on each segment, three for the longest segment 23, and each lug unit is composed of two equal members transversely in line with each other. The shell segments are also divided, in a middle plane normal 50 to the axis of rotation, into equal members 36 and 31.

Widthwise adjustment of the outer drum body, to accommodate tire bands of different widths, is provided for by equipping the respective pairs ol lugs each with a tie-plate 38, formed in its two ends with transversely elongated slots 39 occupied by the stems of bolts 40 which may be loosened when an adjustment is to be made and then reset at the new spacing. The gap between the two halves 36, 37 of each shell segment is bridged by a thin shield 4I which is fastened by screws 42 upon the section 37 and overlaps upon the opposite section 36. The circumferential spacing of the lug pairs 35 is such as to permit the free ends of the two end segments 24 and 28 to fold against the inner surfaces of the next adjoining segments 25 and 27 respectively and to permit the heel end of the segment 24 to iold against the inner periphery of the segment 26, without interference, as represented in Fig. 5. While a greater or less number of segments may be used to make up the outer drum body, it is preferred to employ not less than ve as herein illustrated, in order to fold or collapse it within the minimum compass.

The detachable bead rings 23 are formed with cylindrical portions constituting the marginal or end portions of the outer periphery of the drum, and are further formed with undercut portions 43 and radial inner flanges 44 constituting the seating portions for the beads and adjacent carcass walls of the tire band. Each ring 23 is divided along radial and semi-radial lines into segments 45, 46, 47, of which four is a sufficient number, as illustrated in Fig. 1, in a manner analogous to the construction of segmental tirebuilding cores. Alignment of the segment 45 with its two neighbors 46 may be maintained by dowels 48, as shown at the left in Fig. 1. The key or wedge segment 47, having end facesl which are nearly parallel and slightly convergent outwardly, is guided or gibbed, at least at one end, to maintain transverse alignment with the neighboring segment 46, by means of a tongueand-groove guide 49, and is forced into and out of position between the ends of the segments 46 by means of a pair of manually-operated togglelever devices 56, shown in the extended position in Fig. 1 and in the broken or partially folded position in Fig. 3. Each of these devices consists of a telescopic spring plunger link l pivoted at 52 near the end of segment 47 upon its inner flange 44, and a lever bar 53 pivotally connected at 54 with said link and having a forked end 55 by which it is detachably fulcrumed upon a pin 56 on the inner flange 44 of segment 46.

Each bead ring 23 has its edges fitted by two concentric circular joints with the adjoining edges of the outer drum body 22 and the inner drum body 2i respectively, in an underlapping relation thereto, in the former case by a plain telescopic stepped joint 57 and in the latter case by a tongue-and-groove interlock joint 58, formed between the margin of a wing member on the inner drum body 2| and a conical locking flange 59 on the bead ring, in a manner analogous to that disclosed in my Patent 2,073,729 o March 16, 1937. This form of edge connection, while providing proper alignment of the bead ring segments and mutual support between them and the drum bodies, permits the bead ring segments to be successively detached radially inward from the drum bodies, in a slanting inward course which follows the direction of the undercut beads, beginning with the key segment 47 and followed by the two segments 46 and finally the segment 45 after their end dowels 48 have been disconnected by a short circumferential shifting of the segments 46.

The improved collapsible drum 2| which I have here illustrated as the inner body or core of the combined structure, is made with a central, twoarmed spider or segment support 66 whose hub is fastened by a set screw 6| upon the drum shaft 26, as shown in Fig. 8. A pair of opposite segments 62, with ends overlapping those of adjacent segments, have long hinge arms or lugs 63 in pairs pivoted at 64 upon the ends of the spider arms 66. There is also a pair of opposite, articulated segments, each composed of a member 65, floatingly supported on the adjacent overlapping segment 62 by a hinge connection consisting of a pair of pins 66 connecting the lugs 63 with a pair of lugs 61 of said segment member 65, and a segment member 66 hingedly connected at 69 with the free end of member 65, and having its outer end in underlapping relation with that of the other segment 62. The two series of segments 62, 65, 68 form opposite, symmetrically disposed groups. A control sleeve 70 rotatably surrounds the drum shaft 26 and is adapted to be retarded with relation to the latter by suitable means, such as a brake (not shown), as in my aforesaid Patents 2,042,498 and 2,020,497, when it is desired to collapse the drum. A pair of short links 7| pivotally connect the leading underlapping segment members 68 with toggle arms on sleeve 70, and a pair of long, bent links 72 pivotally connect the underlapping segments 62 with said sleeve. Pivotal articulation of the underlapping segment members 65, 68 in each group aiords a reduced dimension of the contracted drum at both ends of a minor diameter thereof, as compared with former arrangements.

For widthwise adjustment of the inner drum body, coordinate with that of the outer one, each of its segments is made in three parts including a middle or base segment 73 stiffened by an outwardly projecting central rib, a pair of wing segments 74 seated on the depressed portions oi said base segment, alongside of its middle rib, and interior cap screws 75 having stems radially mounted in the wing segments and occupying transversely elongated slots in the base segment for fixing said wing segments at the desired lateral adjustment as is customary in tire-building drums and illustrated in each of my aforesaid patents.

When the inner structure 2| is to be used as the body of a tire-building drum, without the concentric outer body 22, it may be provided, as illustrated in Fig. 10, with the customary gap shield 4| to bridge the crevices at the inner edges of its wing segments 74 and provided at each edge with a segmental, flanged bead ring 23a, such as one of the undercut type, detachably interlocking, through a tongue-and-groove connection 58, by outward movement of its segments, with the edges of the wing segments 74, in a manner analogous to that previously described for the segmental bead rings 23 and substantially as disclosed in my aforesaid Patent 2,073,729; or the detachable bead rings may be substituted by the xed or integral, shallower, depressed bead-seating iianges 231, illustrated in Fig. 11, as ordinarily found in tire-building drums.

In the operation of that form of my invention which includes the inner and outer segmental drum bodies, the outer body 22 is unfolded and established in endless annular form, with its end segments 24 and 28 connected by the tie-plates 32 and all segments uniformly set at the desired widthwise adjustment and secured by manipulating the fastenings 38, 40.

Said 7b,

outer body is then mounted upon the inner drum body 2l, which remains upon the tire-building machine shaft 2li, While said inner body, Whose width has been fixed to correspond with that of the outer body, is in a collapsed condition, and said outer body is axially positioned so that when the inner body is expanded and the bead rings 23 applied, the intertting edges of the two drum bodies and the bead rings will properly register at the joints 5l and 5t. The inner drum body is then expanded by holding the control seeve or collar 10 while the shaft 2li is reversely rotated, thus forming its segments into a circle against the radial spacer lugs 35 of the outer drum body. Finally, the bead rings 23 are applied to the combined drum bodies, one segment at a time, beginning with the segment d5 in a bottom position, then the segments. d?, fitted to 45 by means of the end dowels 28, and then the key segment 6l, which is forced outwardly into position between the upper ends of the segments i6 by stepping the forked ends of the levers 53 of the toggle devices ai! upon the pins 5S while said toggle devices are bent as represented in Fig. 3, and then straightening said toggle devices as shown in Fig. 1, against the pressure of the springs in their telescopic links 5 i, the nnal position of the toggle devices being slightly over-center so that they will remain in the extended condition. When the complete drum is thus assembled in circular form, the bead rings are locked at the joints 58 against axial separation from the inner and outer drum bodies, the outer body 22 is held, by the inner body 2l, against radial collapse by the tool pressure during tire-building operations and both drum bodies are further supported, by the bead rings 23., against radial inward pressure.

The tire band is then built upon the drum and when completed the latter is stopped, and collapsed by reversing the foregoing operations, the bead rings being first withdrawn, beginning with their key segments lll, the inner drum body 2l being next collapsed by bending its toggles lil, li, 'l2 through relative retardation of control collar 'iii with respect to the shaft 2d after the manner of known tire-building drums, to the rolled-up or convolute condition represented in Fig. 9, which permits the outer drum body 22, with the tire band thereon, to be removed from the nner body, and the outer body being then collapsed to the condition represented in Fig. 5, after removing its end connector plates 32, and withdrawn from the tire band.

W'hen using the inner core or body 2l as the body of a tire-building drum 'Without the outer drum body 22, said body 2| will be provided with a gap shield 4l and with either the detachable bead rings 23e of Fig. l0 or the xed bead flanges 23b of Fig. l1, and operated substantially as is customary with tire-buildingr drums of this general type, as disclosed in one or more of my aforesaid prior patents. The improvements of the present disclosure, including a suitable outward location of the floating hinge pins SS and relation thereto of the bends in the links 'l2 which control the overlapping segments 62, together with the articulation of the underlapping segments in a pair of hingedly connected members e5, S8 and application of the shorter toggle links 'H to the leading or free ends of the members 68, permit the said articulated segments to be bent and their members 68 to lie very snugly with relation to segments 62 and the central structure, as will be evident from Fig. 9, and thus provide a greater relative extent of collapse than heretofore, without complicating the structure beyond therprovision of articulated underlapping segments.

It will be understood that the Various forms which my invention might assume without departing from the scope of the claims are not limited to those herein illustrated and described.

I claim:

l. A tire-band building form comprising an inner, segmental form body collapsible to contract its periphery, and an independently collapsible outer form body demountably supported on said inner body, said outer body being composed of a series'of segments connected With each other independently of the inner body, forming an annulus removable as an expanded unit from the collapsed inner body and including a pair of end segments Yand means also independent of the inner body, separably connecting them in the expanded condition.

2. A tire-building drum comprising independently collapsible concentric drum bodies of which the outer is demountably supported on the inner one, and independently collapsible bead rings fitted on the ends of said bodies.

3. A tire-building drum comprising independently collapsible, segmental, concentric, inner and outer drum bodies of which the outer is demountably supported on the inner one, and a pair of undercut bead-seating rings fitted on the ends of said bodies and each composed of segments separable from the latter by an inward radial movement.

4. A tire-building drum comprising an outer drum body composed of segments hinged together in series and having means for separably connecting end segments thereof, a concentric, segmental, `'collapsible inner drum body of narrower width provided With locking edges, and a pair of bead-seating end rings each composed of segments having a circular joint with one edge of said outer body and formed for interlocking engagement, by an outward radial movement, with the corresponding edge or said inner body, in another circular joint.

5. A tire-building drum comprising independently collapsible, segmental, concentric inner and outer drum bodies, and a pair of bead-seating rings fitted on the ends of said bodies and each composed of segments formed for interlocking engagement, by an outward radial movement, with the edge of one of said drum bodies, against axial separation therefrom, and including a slidable key segment, and means for forcing said key segment outwardly into place between the ends of adjoining bead-ring segments.

6. A drum according to claim 5 in which the forcing means consists of a pair of toggle devices interposed between the key segment and adjoining segments and having lever members removably iulcrumed on said adjoining segments.

7. A tire-building drum comprising an inner,

segmental drum body mountable on the shaft of a tire-building machine and collapsible and lexpansible while in place on said shaft, a concentric, outer, collapsible, segmental drum body supported on said inner body and removable as an annulus therefrom, together with the formed tire band, when the inner body is collapsed, and removable bead-seating rings fitted on the ends of said bodies.

8. A tire-building drum comprising a collapsible outer drum body, removable end rings thereon for forming relatively deep bead skirts on the tire band, and an inner drum body normally concentrically supporting said outer body and including not less than six segments collectively collapsible to a reduced periphery, permitting removal therefrom of the uncollapsed outer body and formed tire band.

9. A drum according to claim 8 having a segment support for the inner drum body, and means including a relatively rotatable control member for radially collapsing the segments of said inner body upon each other, away from the outer body.

10. A tire-building form comprising an inner, radially collapsible form body composed of segments each adjustable as to width, and an outer, radially collapsible form body concentrically surrounding said inner body and including segments each divided longitudinally into a plurality of members, means for xing said members at different widthwise adjustments coordinate with those of the inner form body, and shield segments overlapping said segment members of the outer form body for bridging the gap between said members at their various widthwise adjustments.

11. A form for sem-at tire-band building comprising a rotary segment support, and a drum body having two similar groups of overlapping and underlapping segments pivotally and symmetrically mounted on opposite sides of said support, and collapsible in a double convolute to l reduce the eiective outer circumference of the drum, certain opposite segments being articulated to obtain a minimum collapsed circumference.

12. A tire form according to claim 1l in which 1 the underlapping segments are articulated with hinged toe members and collapsible simultaneously at opposite sides of the drum by means of a relatively retardable central collar linked to both toe members. 20

HENRY C. BOSTWICK. 

